Posted
by
CmdrTaco
on Wednesday August 15, 2007 @08:55AM
from the that-sure-doesn't-look-good dept.

Roland Piquepaille writes "Neptec Design Group, a Canadian company and a NASA prime contractor for 25 space missions, was kind enough to send me exclusive images of Endeavour's damaged tiles during its last take-off. So here are some of these pictures" The pictures are pretty amazing and make the urgency of this whole thing much more amazing.

On NPR this morning, I heard that NASA was actually debating whether or not to even address this, as they did not want to go to all the trouble and spoil the shuttle's schedule.

This sounded especially insane to me...if NASA loses another shuttle because of this same tile-damage problem, and because they couldn't be bothered to take the time to fix the problem when they could have, it will be the end of NASA.

Very good point. I remember back in the early 80's news reports of the shuttle coming back with 1/3rd of the tiles being gone due to faulty glue. Even when they didn't need to repalce the tiles so much, I'm sure they HAD to go over every inch with a fine tooth comb, and I'm sure that more than once they found some with holes from damage, either ice or micrometers. This whole "omg teh tiles have holes in them' thing is a reaction to the columbia disaster, and a way to show the media that 'yes, we are aware of the issue'.

I like the fact that our society is open enough that this information and this debate is public. There are many governments in this world today who would not allow this information to be released and would make the decision based on cloaked objectives and goals. The USA has its problems (e.g. the stupidity of Iraq) but it sets us apart that this is happening in the open. Nobody is going to get arrested for debating or questioning this intense and sensitive topic.

It always amuses me how the masses sitting on the sidelines always feel they can do better then the trained professionals. I'm assuming you've already done the calculations between risk of the loss of them doing a spacewalk vs tile damage, where the tile is positioned, and taken into account the fact before Columbia that tiles fell off without incident. I could be wrong, but I'm just as qualified as you are. So is the guy I bought a hotdog from yesturday for that matter.

This would be like my mom telling me she can do computer support better then me. She's a smart lady, but her KNOWLEDGE level when it comes to Computers is low.

If they're typical tiles and they haven't drastically changed things from the demo they have down in Florida that I looked at 10 years ago, they're 3 or 4 inches on a side. The NPR story this morning said the gouge was 3" long.

It looks borderline to me. I think they've successfully landed with much bigger gouges or missing tiles in the past, but it probably depends on WHERE the gouge is. If it's in a flat part of the belly, it's probably not a problem. If it's near a leading edge, more of a problem.

They are in the wind tunnel doing test studies on a similar gouge crafted from the laser data taken on Monday. The Shuttle people know what they are doing. You have to remember, this gouge was downgraded from the size stated earlier this week, its only about the size of a business card, half the size that was being reported on Monday and less a quarter of the size that was thought to have dealt Columbia in.

You also have to consider position. This is at the very rear of the vehicle. Reentry heating evironments are most severe near the stagnation point at the front of the vehicle. Towards the back you can actually get some recirculation that provides some cooling. It may not be worth the risk/reward to go and patch it, based on locale. I guarantee you if this was on the front of the orbiter, it would be a whole different story.

Astronauts have balls of steel to begin with. Two sets. You're sitting, surrounded by just how much in explosive fuel? Blasted into one of the most uninhabitable climates for human survival. (Ranks up there with volcano caldera and bottom of ocean...) Then set on a 100 mile free fall course to the Earth, the same trip many meteors take, and burn up well before hitting the ground most of the time.

... he'd be standing on top of a table right now screaming about something, NASA shuttle in space or not. He was a pretty intense kind of guy who could get away with standing on tables, soap boxes, and other tall things.

True. He was a passionate guy who cared about things like that. He also had startling insight and an annoying habit of being right most of the time.

Limbaugh says "there's a theory going around" and after explaining it says "a lot of people are beginning to think that the banning of Freon actually caused the shuttle accident, the Columbia shuttle accident, two flights ago. And I'm inclined to believe it when I hear this." This was on August 3rd, according to media matters. At this point the NASA report had not been released yet--it wouldn't be fully released for months! There was nothing to lie about!

Can someone really "lie" when they say "there's a theory I'm inclined to believe" ?

But I suppose it's just much easier to hysterically claim that Rush Limbaugh both originated the theory AND lied about it that to actually read your own link though!

Don't try to explain physics to these dorks, they won't get it. Most of them consider/. the intellectual part of their day, right between belittling users and arguing if Batman could REALLY beat up Superman.

As a trained project manager,I have to take issue with this statement. I do think that NASA suffers from management who makes risk calculations with too much consideration of 'the schedule' verses the risk of life. However, NASA has done a valid risk mitigation step by examining the shuttle after takeoff and trying to determine what to do. Most sensible people can do the risk management required by asking a few questions. What is the risks? What are the chance of those risks being realized? How can we mitigate those risks? Those analysis steps are done by engineers, but it comes down to the manager who has to give the go/no-go decision. 10% risk of catastrophic failure? Ok, what are the other options?

Stuff like this requires more significant then six sigma quality (3.4 defects per million). The CMS puts a 0% error rate requirement on certain measures for hospital quality. Does someone presenting heart attack symptoms get an aspirin within the first 24 hours of being in a hospital? Do they get a beta blocker within 24 hours? 0 variations are allowed to meet their quality goal. Six sigma level quality would have 1 variance out of large hospital's annual patient level of patients presenting heart attach symptoms, which is unacceptable by the standard. Set a risk measure and goal for shuttle tiles, for example - 0% risk of a tile related catastrophic failure upon re-entry. Then make the engineers plan for how they will achieve it. If the engineers fail at achieving this, causing a catastrophic failure, start license removal procedures on the engineer that signed off on it, followed by criminal charges.

It's more like the engineers got hamstrung by the Air Force and the beancounters. Original shuttle plans called for a fully-reuseable vehicle with a more robust thermal protection system. The beancounters promoted the half-disposable design we have now, claiming it would reduce costs, and contrived studies to show that it would be much more reliable than it actually turned out to be. They also screwed around with the budgeting, eventually causing even more cost overruns, delaying the development, and forcing compromises that made the vehicle less safe.

The Air Force wanted manned space capability, and offered to help pay for the development if they got some say in the design and were allowed use of the shuttles when built. The USAF insisted on a larger payload bay (60ft long, as opposed to NASA's 40ft plan), which obviously made the vehicle larger. They also wanted the ability to land at the launch site after a single polar orbit, requiring 1000+ miles of crossrange. This led to the heavier delta wing and higher reentry heating loads.

We wound up with a vehicle that was larger, more expensive, and less safe than we should have. The engineers did the best they could under the political mandates they were given.

The problem with the shuttle is not any specific design decision it's the overall design goals which the "top-end engineers at NASA" had little to do with.

"The crucial factor in the size and shape of the Shuttle Orbiter was the requirement that it be able to accommodate the largest planned spy satellites, and have the cross-range recovery range to meet classified USAF mission's requirement for a one-around abort for a polar launch." The most obvious bad design decision was to send cargo up in a manned mission. Manned vehicles cost a lot more per pound sent to space than unmanned so mixing the two increases the cost of sending stuff to orbit with zero real gain. The other issue is the requirement for a polar orbit. (Think Russia) Getting people to space is hard but doable getting people to space and a polar orbit is a much harder task that is a waste of resources 99% of the time.

Second "Each Shuttle was designed for a projected lifespan of 100 launches or 10 years' operational life." However, Discovery was built in 1985 its last flight is scheduled for 2010.

If you want a cheep reusable rocket rebuild the shuttle with 5% its cargo capacity, a slow reentry, and skip the polar orbit concept and you get a much larger safety margin and a much less extreme operating environment and a lower cost per person to orbit.

Both of the deadly shuttle accidents are directly attributable to the side-by-side nature of the orbiter and the fuel tanks and SRB's. This design should have been discarded. If the shuttle were stacked vertically, these particular failures would have been impossible.